Grinding machine

ABSTRACT

A grinding machine having means for memorizing retraction movement and re-introducing it minus a preselected amount.

United States Patent 1 1 1111 Robillard 1 GRINDING MACHINE [75] Inventor: Edward G. Robiilard, Cherry Valley, Mass.. 1 g Cincinnati Milacl'on'ueald 1 Prir nary ExaminerHarold D. Whitehead corporatwn, Worcester, Mass- Attorney, Agent, or FirmNorman S. Blodgett; Gerry 22 Filed: Mar. 8, 1974 Blodge" [21] App]. N0.: 449,224

[52] US. Cl 5l/l65.77, 5l/165.87 57 ABSTRACT [51] Int. Cl B24b 49/16 [58] Field of Search 51/165 R, 165.77, 165.8,

51/165537, 16593 A grindlng machine havlng means for memorizmg re- 7 traction movement and re-introducing it minus a pre- [56] Reerences Cited se1ected amount.

UNITED STATES PATENTS 3,503,158 3/1970 Robiliard 51/165.8

14 1 Feb. 25, 1975 5/1974 Nagashima ..5l/l65.87X 8/1974 Sanford ..5l/165.87

10 Claims, 39 Drawing Figures PATENTEU P56251975 a, 867. 794

SHEET [310F31- MIMI! v FIG. I

FIG. 2 25 1/ H FIRST SIZE 5ECD|ND SlZE u Q 42 PATENTEU M51915 3,867, 794

SHEET UZOF 31 MULTIPLE FEED POSIT -00! ON DIA, muss s u ur I h L I \9 PICK FEED COMFENSATION EEEEE 0N (MRI! rm; .amanuu PAIENIHJ 3. 8 67, 7594 saw 03 0F 31 FIG. 4

FIG; 5

PATEm nrzaasms 3, 8 67. 794 SHEET GS'UF 31 FIG. 9

F I6. I O

H FEED RATE Y Y Y-RETRACTION POINT A cl CONTROLLED X FORCE x E DRESS F @?0 0 COMPENSATION FIG. 34

PATENIEB FEB 2 5 I975 sum 06 0F 31 3.867.794 SHEET 07IF 31 PATENIEB FEB2 51975 mojw wmomo PAIENIED 3255173 3, 8 67, 7' 94 SHEET l3OF 31 BOARD EJECTOR I2l I22 I23 I24 PRINTED M 2 l I CIRCUIT O I I BOARD I I 0 I00 OHM WATT RESISTOR R2 IK '/z WATT I00 RESISTOR Io OHM /2 WATT E 0R [1 R 8:81

B IOK /2WATT R|5 Q Q Q m R5 RESISTOR Ioo mo 3 Io H6 H7 H8 H9 0: a: lo I l nr'lnf'll'ln FH'H lnnnnn II "c"34| agg m DUAL JK I26 I25 FLIP-FLOP 2 I27 I27 R6 8 v FH'IFH'IYIIIFH'! flllfifll'lnfi m 3.aI wAT T a x x EXCLUSIVE RESISTOR mum f u QUAD 2 DIODE 4mm INPUT GATE IN 4003 II qEP 2l-7335 93 COMPONENT SIDE I BOTTOM SIDE IIIIIIIII IIII I STUVWXYZ FIG.I4

PATENIEI] FEB 2 5 I975 DUAL 5 INPUT BUFFER QUAD 2 INPUT BUFFER WITH RESISTOR DIODE .HIII IIU DUAL JK FLIP-FLOP QUAD 2 INPUT GATE FIG.I6

PATENIED FEB2 5 I975 sum 16 0F 31 t 5 55 i 5% O1 5 .0 PE 85 BCD DECADE DOWN COUNTE R PATENIEQ FEB 2 5 H375 sum 17 0F 31 CAPACITOR FIG.I8

PATENTEDFEB25 1% 3; 8 57. 794

SHEET 18UF 31 GND. 5 z 4TMFD c4 2RR U R MEMORY RELAY v M FEED RELAY IN4003 v 7 w PULSE OUT w E B R-l5 82K 06 9 IO 9499C 07 s H 2K IOK H :90

\ mews 6 E PULSER STOP R-3 330 B 3mm ll Y 2K 4.7K E 4 1E 09F V 00K IN4003 5: g

X TIMER STOP PULSE T TIMER START A RESET PATENTEDFEB25I975 3; a 67, 794 SHEET 19 0F 31 QUAD.2

IWPUT GATE =|E|= =El= DUAL ONE SHOT DIODES |N4003 CAPACITOR .IMFD

QUAD 2 INPUT BUFFER DUAL 5 INPUT a BUFFER 4 1 47MFD nnnnnnnnnnnnnmmnnnnn CAPACITOR 

1. A grinding machine for the finishing of a surface of revolution on a workpiece, comprising a. a base, b. a workhead mounted on the base for supporting the workpiece, c. a wheelhead mounted on the base for carrying a spindle with an abrasive wheel, d. a dressing apparatus, e. control means bringing about relative movement between the wheelhead and workhead longitudinally and transversely of the axis of the said surface of revolution to produce a grinding cycle between the wheel and the workpiece, the cycle consisting of a rough grind, a dress, and a finish grind, f. means connected to the control means to determine a point of termination of the rough grind when the surface reaches a predetermined size, and g. means measuring the distance from a predetermined point to the point of termination of the rough grind, backing the wheel that same distance for the dressing operation, and later returning the wheel that same distance minus a preset distance, so that the finish grind can start without loss of time and without striking the workpiece prematurely.
 2. A grinding machine as recited in claim 1, wherein the said preset distance is determined by a digital switch mounted on the front of the machine and adjustable by the operator.
 3. A grinding machine as recited in claim 2, wherein the front of the machine is provided with a digital readout which shows at all times the transverse positional relationship between the wheel and the workpiece and which gives a reading of ZERO at the end of each grinding cycle, so that the operator can observe any differences between successive cycles.
 4. A grinding machine as recited in claim 1, wherein the transverse relative movement between the workhead and the wheelhead is produced by a stepping motor.
 5. A grinding machine as recited in claim 4, wherein the means connected to the control means is a gage, and wherein a feed means forming part of the control means is provided for pressing the wheel against the workpiece with a controlled force during an initial major portion of the rough grind.
 6. A grinding machine as recited in claim 4, wherein a generator is provided to transmit electrical pulses to the stepping motor, wherein a memory counts the number of pulses transmitted from the said predetermined point to the termination point when the gage indicates that the predetermined size has been reached, and wherein the said number of pulses is partially reintroduced in reverse to the stepping motor to return for the continuation of grinding.
 7. A grinding machine as recited in claim 6, wherein the wheelhead table has a second stop which engages the compensation slide at a second point in the relative movement between them.
 8. A grinding machine as recited in claim 7, wherein a control introduces a preselected number of pulses to the stepping motor as a compensation before dressing, introduces and memorizes a number of pulses to move the compensation slide the said distance from the predetermined point to the point of termination of the rough grind, reintroduces the same number of pulses in reverse mode to the stepping motor before dress, and reintrodUces the same number of pulses in direct mode to the stepping motor after the dress.
 9. A grinding machine as recited in claim 8, wherein the control also introduces a number of pulses in direct mode to the stepping motor for a reset movement of the compensation slide before the rough grind and reintroduces the same number minus a preset number of pulses in reverse mode for a retract movement after dress.
 10. A grinding machine as recited in claim 9, wherein a hydraulic cylinder is provided to produce rapid movement of the wheelhead table relative to the compensation slide from the first point to the second point and vice versa, the cylinder being operative at the termination of the rough grind to produce the movement in one direction before dress and being operative before the finish grind to produce the movement in the other direction after dress. 